Link between assisted reproduction techniques and genetic disruption

Evidence that assisted reproduction techniques may carry a risk of genetic 'imprinting disorders' in the resulting babies, emerges in a study published in the Journal of Medical Genetics.

To assess the likely risk of genetic disruption, geneticists from the University of Birmingham and the West Midlands Genetics Service assessed the birth histories of 149 babies with Beckwith-Wiedemann syndrome.

Features of Beckwith-Wiedemann syndrome include overgrowth, abdominal wall defects, low blood sugar, kidney abnormalities, and an increased risk of tumours - up to 10% of children with the syndrome develop childhood tumours, usually in the kidney.

Beckwith-Wiedemann syndrome results from errors in genes which undergo the process of genomic imprinting. This is a process whereby certain genes act differently according to whether they are inherited from the mother or the father. Ones from the father tend to encourage the baby to grow bigger, while those from the mother tend to keep growth in check. Most genes are not subject to imprinting, but the ones that are tend to be involved in fetal development.

The researchers found that children with the syndrome were four times more likely than the general populaion to have been conceived by assisted reproduction techniques, such as in vitro fertilisation (IVF) and intracytoplasmic injection. Six of the 149 babies with the syndrome had been the result of assisted reproduction three with IVF and three with intracytoplasmic injection, compared to about 1% in the general population.

Over 43,000 babies were born in the UK between 1995 and 2000 with the aid of assisted reproduction techniques.

The authors note that another type of imprinting disorder, Angleman syndrome, has also recently been linked to assisted reproduction techniques, and suggest that as the use of these techniques becomes more widespread, it will become increasingly important to monitor subsequent births for genetic problems.